Japanese Unexamined Patent Publication No. 2008-101530 discloses an exhaust device for a supercharged engine including an exhaust outlet port formed in a lateral surface of each bank of a V-shaped engine in the cylinder array direction; a supercharger connected to each of the exhaust outlet ports; an exhaust pipe extending from each of the superchargers toward the rear side in the vehicle front-rear direction, and configured that downstream ends of the superchargers are connected to each other; a collecting pipe extending from a connecting portion of the exhaust pipes toward the rear side in the vehicle front-rear direction; and an exhaust gas purification device provided at the collecting pipe.
In the exhaust device for a supercharged engine described in the publication, the exhaust gas purification device is disposed far away from the engine toward the rear side in the vehicle front-rear direction. Therefore, the temperature of exhaust gas may be lowered before the exhaust gas reaches the exhaust gas purification device. As a result, the exhaust gas purification device may not exhibit a sufficient purification performance. Further, it is necessary to dispose an exhaust gas purification device below a floor panel of a vehicle body, and it is necessary to bulge the floor panel toward the inside of a vehicle compartment in order to secure an installation space of the exhaust gas purification device. This may reduce the space for the vehicle compartment.
In view of the above, there is proposed an idea of shortening the distance between an engine and an exhaust gas purification device by installing the exhaust gas purification device laterally of the engine to prevent lowering of the temperature of exhaust gas.
However, in order to install an exhaust gas purification device laterally of an engine, it is necessary to install the exhaust gas purification device in a space along a lateral surface of the engine while avoiding interference with a supercharger and an exhaust pipe (i.e. a duct for connecting the supercharger and the engine). This may limit the installation space of the exhaust gas purification device, and it may be impossible to sufficiently secure the installation space.